Stapler



FIG. 1 is a side elevational view of the left side of a stapler showing my new design, the right side being a mirror image of the left side;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a top plan view thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a stapler, as shown and described. 